He’s also my business partner. He kept his watch collection with me since his wife doesn’t allow him to buy watches and made me promise not to ever tell his wife about them. Not only because she doesn’t like it but also because she will definitely ask him to sell them and probably spend the money on clothes and traveling like she often does.
He lets me use the watches in the condition that I don’t cause any damage. But now that he passed away it doesn’t feel right any more.
His watch collection is worth about 200K$ in todays market. I think the lawful and ethical thing to do is to break the promise and tell his wife but I’m not sure that’s the right thing to do since he made me promise not to tell her.
I think the other comments have established pretty clearly that they belong to your friend’s wife. One small thing from personal experience- are you sure they’re genuine? My FIL passed away, and there was a secret watch collection nobody knew about. Turned out a lot of them were replicas, although not all. It meant the financial consideration was pretty small compared to what we’d expected at first.